1. Related Patent Applications
U.S. Pat. No. 4,827,411 by A. H. Arrowood et al, issued May 2, 1989, and entitled "Method of Maintaining a Topology Database" discloses a technique for maintaining a common database of information distributed at plural nodes of a network relating to the topology of physical links between nodes as well as the topology of physical and logical resources at said nodes.
Copending patent application Ser. No. 062,280 by A. E. Baratz et al, filed June 15, 1987, and entitled "Method for Exchanging Network Control Information," discloses a technique for facilitating the flow of control information between nodes in networks capable of distributed control.
2. Field of the Invention
The present invention relates to computer networks. More particularly, it relates to a method for finding a target resource in a network.
3. Prior Art
Computer networks for processing and transmitting data are well known. A typical computer network system comprises at least one host computer running under some type of operating system, communication controllers, communications media and a plurality of end users (terminals, printers, displays, etc.). The host computer is connected, via communications media, to either a communication controller or an end user terminal. The communication controller interfaces with other communication controllers or end user terminals via communications media. The communications media may be telephone lines, channels, satellites, etc. By entering a request at a user's terminal, the user may extract data from the host computer. Similarly, a user may enter information on a terminal through which it is transmitted to a host computer for processing and/or to another terminal in the network.
Computing systems are controlled by a system architecture that ensures the orderly flow of information throughout the system. The prior art describes several types of architectures. For example, an overview of the architecture used in computer networks is given in an article entitled, "Computer Network Architecture," by S. Wecker in Computer, September 1979. Another overview, including a description of System Network Architecture (SNA) is given in an article entitled, "An Introduction to Network Architectures and Protocols," by P. E. Green in the IBM Systems Journal, Vol 18, No. 2, 1979. In these articles, the various computer networks such as SNA DNA, ARPANET, etc. are described by means of hierarchical architectural layers, where the lowest layer relates to the physical communication lines interconnecting various user nodes of the network and where the highest level concerns the conversation per se between the various end users of the network.
As networks become more dynamic, the addition and relocation of resources and end users occur more frequently. New procedures are needed to allow customer networks to grow and change more easily. Among other things these procedures must minimize the amount of coordinated system definitions needed and tolerate errors and race conditions in the network.
An article by Baratz et al entitled: "SNA Networks of Small Systems," IEEE J. Selected Areas in Communications, Vol. SAC-3, No. 3, May 1985, addresses the minimization of coordinated system definitions. However, it does not address adequately the means and methods to accomplish the minimization.
Further information on SNA terms and concepts can be found in Systems Network Architecture Technical Overview, IBM Publication GC30-3073-2, September 1986.